For those of you with British Isles ancestry, here's a fascinating online tool: the Surname Profiler. It shows you the geographic distribution of a surname in England, Scotland and Wales in 1881 and 1998. My maternal ancestors, the Adam family, knew where the came from:

Odious' tribe hales from balmier climes:

(Hat tip: Laputan Logic.)

Update: Damn! The maps won't display in proper arrangement in some browsers. Anyway, the first is Adam 1881, second is Adam 1998, third is Odious' family 1881.